Improved revolving furnace for roasting ores



2 SheetsSheet 1.

REVOLVING FURNACE FOR ROASTING .ORBS. A No 81,762. Patented se t. 1, 1868.

Z I 3 Z222 frzweiu an TO ALL WHOM I1 MA YQGONGEEN:

DE IQK EBNS T,"0F SAN FRANCISCO, CALIFORNIA.

LetterePatent lVo. 81,762, dated September 1, 1868.

IMPROYED- nnvoLvrnc FURNAGE ron nons'nuc ones.

at '5tlgthult Itfttlth'itilt tints Enters 33mm irritating and at flgt same.

Be it known that}, FRBDEIIIGK EIiNSr, of the city and county of San Franciscm State of California, have invented an Improved'Be vol'ving Furnace for. Roasting'Orcs; and I do hereby declarcthe following description and accompanying drawings are sufiicient to en-able any person skilled in the artor science to which it most nearly appcrtains to make and use my said inventionor improvements without further invention or experiment.

My invention consists in providing a mechanical furnace for roasting or treating ores, which does away with manual labor, with the exception of a fireman.

By the use of my furnace and apparatus, the ore is roasted, stirred, charged, and. discharged, and in fact performs all the operations required inthe oxidation or chlorination process of roasting gold or silver ores,

The ore is taken from the battery or stamps by means of an elevator, and discharged constantly and regularly intoa hopper, frou whence it falls upon the rotating hearth of the furnace. s

The fire-grate is stationary, and the heat passes around 'in an opposite direction to the travel or the rotating hearth, and the ore, when sufficiently roasted, is discharged: at one side of the fire-grate by revolving scrapers.

To more fully illustrate and describe my invention, reference is had to the accompanying drawings, and letters markcdthcreon, of which- Figure I is :1 plan, with hearth removed.

Figure 2 is an enlarged view of the discharging-apparatus. Figure 3 is a sectional elevation. Figure -i'is a bottom view of the hearth. Similar letters of reference in each of the figures indicate like parts. I The foundation, A, may be constructed of ordinary masonry, ofthe desired form. I prefer a circular shape, with a'circular ccntro for the rotating apparatus, as shown in the drawings, with inner and outer walls,v

B .G, nii'ordingsulficient space for the travel of the rotating hearth.

' The hearth, ,D, consists of an annular or orbicular ring,'pa.vc d with brick, or it may be constructed of iron plates iri scctions, surrounded withv flanges or projeotions,'E E.

The inner circumference of the bottom of the hearth is providcdwith-a circular-toothed rack, 1i, and a circular fiange, G, is made in the centre, which operates .in a series of grooved friction rollcrs li H, on the roadway beneath.

The hearth is made to revolve by the pinion I engaging the teeth on the'circ'ular rack: v The shaft-I'of the pinion passes through the inner wall of the furnacc, and is provided with a. pulley, J, which may be a change-pulley for a belt-connection'withthe engine or powerfor driving the apparatus, and increasing ordiminishingthc speed of'the hoart h, as desired. I

Thc'top of the furnace, when constructed, foruls a continuous drch, K, fig. 3, sheet 2, and is provided with .a'llue, L,;ncar the feed-hopper, and. suitable openings for the draught-regulators or stirrers, and dischargingapparatus. I i 1 The stirrcrs, M, one or more, are placed across thc'heurth, so astc nearly touch the circular pathway, and turn the ore, having hearings on the walls B C, and are operated by a wheel on the shaft I, and pinion at the end of the stirrer, and as the hearth is revolved, the ore is carried upon the stirring-plates and falls bacli'upon the hearth on the other side. These plates may -be replaced, as fast'as they become worthless by the action of the sulphur upon their-on. r I Thedischarging'apparatus is-placedtransversely across the hearth, and consists of iron scrapers, N connected to endless chains, N, passing over arms onwheels, having hearings on the top of the furnace. J This apparatus may be arranged so as to be elevated or lowered, or its operation stopped entirely, as in case the ore is not sufliciently roasted by one revolution .of the hearth, or it may be elevated so as to discharge the top portion ofthe ore at the op ening O that has been subjected tc the direct action of the heat from the fire-grate, and allow the under layer to pass on to perform another revolution.

.end at each side of it are plhcedslid'es 'or dampers, U U,"

' The fire-grate? is built out at the side of the fui'nncq hlving a flue, Btleading'through the outer wall into the arch ebove therevolvln hearth.

Between the tireflue and the disolinrging-l'ppentus is placed a damper or sliding plate, 8, ,whioh passesthr'o'ugh the top of the we'll, it nslight inoline with the-direction of travel of the hearth, and tiny-serve the double purposeof checking the drought. and stirring the ore, it being regulated by raising or lowering the slide.

lThefeed-hopper'l is placed at the top of the wall, between the oh nay-flue and the dischargingfapparatus,

The slide reprehented at U' mnyserveto prevent the fine particles of oro-dnst'from entering the chimney-l flue as-the ore fella upon 'the hearth, mull) for thepurposoo'f' preventing the duat froin' pnasing out through the oponing-in whioh the diseharging-apporatus works.

To keep constant oirculntionof hir through the furnace, the, oroh over thehearth deereazes slightly from the fire-bridge towards the lines, and it-is intended that suficient air shall headmitted between thorevo'lvjng hearth and the while of the furnace, us we'll es-openingsmade for the operation of the discharging-appeal. to oxidize the ore, end oonsnu e the sulphur and other gases.

v By'this modeof constructing furnaces grout ndvautnges are obtained, among which imy be enumerated, first, doing away withtho costly and imperfect hand-lulior, where it is almost an impossibility to roast a charge of ore well; and, second,- the lnrge saving of fuel, potlalone hy means of the'greot-length of hearth, buttlmt ell the gases which are lost other furnaces are utilized and oon'sumed'v viththe'oxygen oontainedin the atmosphere, whioh is constantly heing supplied through the apnoea, between the hearth and walls, and that, without cooling the one; consequently the ore is muoh sopn'eroxidized; .third,'if the orei s once desulphurized, it will not tie-liable to 'ohsorb ngain the snlphurous genes rshioh emenatqaa they are carried behind by the current as the hearth iii advancing; fourth, 'the loss of silter in sublimation in the present furnaces isnvoided in this, as the silver condenses before reaching the flno's, the distance being great, and tho heat dimiilishing. Having thus den'oribpd niyinvention, what I claim, and-desire to secure by Letters'Pntent, is-

1. The hearth D, revolving between the inner and outer. walla B Q of the furnace, with the circular rnok F and flange-G, operating in the grooves at the rollers HE, subtentially as described.

2. The discharging-apparatus, operating trnusverselyacross the fn ruece, above the rotating hearth,'anu

eonsi's'ting of 'the scrapers N N, attoehed to the endless chaintN', operated hy the wheels, substantially as" described.

.73. The construction of the hearth D, with the circular flange 'E E,-so n: to retain the ore upon the surfnee of the hearth, and the stirrer M, or its equivalent, .to turn the ore as-the hearth revolves, the .whole oonatruoted and operated suhstnntiallya's described. p

4,. The dampers U U(, and sliding pinto S, arranged to be operated euhetantieliy es and for the purposes described. pass in an opposite direction, substantially as described.

In witness whereof, I have hereunto set my hand nnd'seel,

- F. ERNST. [n. 5.] r

Witnesses G. W. M; Swim,

J. L. new.

5. In revolving fnrneeos, eerrying theore in'one direction on the hearth, while the heat, flan-1e; and gases 

